Water-tube boiler.



W. SCHMIDT.

WATER TUBE BOILER.

APPLIOA'IION FILED AIBJZ, 1911.

Patented Sept. 2, 1913.

2 SHEBTB-8HEET 1.

INVENTUH W/LHELM SCHM/DT aw 44 4 K4 1 1 ova/v1 W. SCHMIDT.

WATER TUBE BOILER.-

APPLICATION IILED APRJIZ, 1911,

1,97%,1 M. Patented Sept. 2, 1913.

2 SHEETS-SHEET 5].

-.* ATTUHMFYJ" eat-ion.

UNKTED PATIENT tll lrllltlllll WILI-IELM SCHMIDT, F CASSEL-VJILl-YEIJWSHUHE. GERltIANY. ASQIGNOR T0 SCHMIDT- SCHE HEISSDAMPF GESELLSGI' A'FT MIT BESCHRANIZTCER HAFTUNC-b 0F CitltSfi-SEL, GERMANY, A CORPORATION OF GEIHJANY.

HATER-TUBE BOILER.

i ,072, that. atentedf-ttait.2,1033.

Application filed April 12 1911. Serial No. 620.540.

Specification of Letters Patent.

at the pr ssures proposed being very high, the supcrheatimr must be' carried jl llll'llfil' than has been usual hitherto, so that it becomes necessary to consider temperatures of 400 C. and more. This, of eourse. increases the risk ol the superheating tubes bottoming red hot a condition whielt it is emential to 1 '0 all I /wilt it may centre/'22 Be it known that l, \Vimirmu So'nnnrr. 1 a'snbjeet of the King of Prussia, Emperor of (Tlermany, and a resident of Casset-ll'ilhehnshtihe, Germany, llttVO'lIlVOfil't-ltl a new and useful Improvement in lVater-Tube Boilers, of which the following is a speeitl;

bursting under the high pressure. must therefore be taken that the flue gases do not come into contact with the superheater tubes in too but a eondition. The employment o'l such coo ed flue gases net-essitates however an intense heating oi the supcrheater it it is desired to avoid making the superheater unduly large in proportion to the other elements of the boiler. Finally, it must he rememlmrcd that the heating gases in consequenm: of the high tempora ture neeessitated by the higl'i pressure are still so hot when leaving the superlieater that their immediate exhaust or escape into the chimney would be very unemnomical even in marine boiler installations. Some method of utilizing this excess heat becomes desirable therefore, though it is no longer suitable for generating steam owing to the high boiling point.

My invention, whieh will now be de- -'t'l'lllt'(l. provides an arrangement: in which the foregoing considerations are given full elt'eet.

llet'erriugto the drawings--Figure .l illus trates one Form of the invention in cross section as applied to a marine boiler Fig. 52 is a section taken through a detail on the line 2-" '12 at Fig. l; and Fig. I is a cross section through hall' of a similar type boiler constructed acrording to a modification of my invention.

'lhe boiler shown in Figs. 1 and 2. t'()ll- Y My invention relates to' water tube boilers and especially to such boilers whenprovided with means for superheating, or t'nr both super-heating and heating the feed water.

The object of my invention is to provide a practical water tube boiler capable of generating highly superheated steam at pressures as high as atm. or more; preferably I employ small diametered water tubes insteadaoit the larger tubes commonly used. At such pressures the boiling point of water is considerably higher than at pressures hitherto employed, being (I. r at tit) atm.,. about- 273" as compared with 5300 at 15 atm. Moreover, it must be borne in mind that at high pressure the eireulation at the water is considerably less active. Such. cir

eulation, as is WLll lUlOWIL is brought about chiefly by small bubbles of steam rising during evaporation, but the volume of these small steam bubbles for equal weights oi" Water evaporated, is considerably decreaslul when high pressures are employed. so that: the action of the steam bubbles on the eirculation of the water naturally decreases. Thus at a pressure of (it) aim. the circulation of the Water is only abouthalt as ell'eetire as at a pressure of 15 atm.

The ell'eets of the higher temperature of the mixture of. steam and water and the greatly reduced water circulation combine to lower to a dangerous degree the cooling action of the boiler water on the water tubes and the latter will, tl'ieret'ore, other things being); equal, be strained much more severely at-the proposed pressures than at those hitlr erto employed. These dangerous strains are produced when the tube walls are but slightly overheated.

The etl'ect of the high pressures proposed has also to be considered in relation to the superhealing ot' the steam. The require: .ments, however, in this connection are somewhat ditl'erent from those associated with the generation or steam, since as remarked above the temperature of saturated steam and three lower drums, 13, it and B these sets of drums being connected"with eaeh other by means of the water tubes, (3. The lower drums are separated froureach other by means of grates, R, It. The treating tines a re tornied and bounded by tube walls (shown hatched for greater elearness) l) consisting of Water tubes arranged closely together and comuniniotite with the chira ncy by means ol passages, l). The heating lines are so arranged that the current of hot gases passes through them transversely,

avoid in view ot the possibility oi the tubes bare sists of three upper drums, A, A and l above the furnaee pcrinits the use of a very large number of Water tubes so that even with an excessive demand on the boiler only a moderate heating of the first heating line is necessary. Preferably all the water tubes serving for generating the steam are ar ranged in the first heating flue and it is ad visable in this connection to provide the parallel flues with high inlet openings or to leave them entirely open toward the fur nace, so as to reduce as much as possible the harmful formation of pointed flames where the gases enter the parallel dues. in addition, the arrangement whereby the cur rent of heating gases flows in a direction transverse to the longitudinal axis of the upper and lower drums favorably influences a moderate heating, for this arrangement allows the heating gases to enter from any point of the grate directly into the portion of the heating flues arranged above it. The heating gases will, therefore, not crowd together at certain places, as is the case when they flow parallel to the longitudinal axis of the boiler or in other words, when the heating gases enter the heating lines through an openingarranged at the end'of the grate. This direction of flow of the heating gases also insures all the water tubes of the heatingfl'ues, being heated uniformly a matter of the greatest importance for the required moderate heating. If the heating gases were allowed to flow parallel toithe longitudinal. direction of the boiler, then the Water tubes situated at the inlet of the heating lines would be subjected to a strain considerably greater than the water tubes situated at the end of the heating flues.

The large heating surface provided in the first heating flue sufficiently insures the heating gases being cooled down to the low temperature desirable for the superheater. 0n the other hand the contraction (as re gards cross sectional area) to which the heating gases of the two parallel fines are subjected when passing through the superheater flues results in a substantial increase in the velocity of the heating gases, so that the heating of the superheater when of moth crate dimensions becomes intense. Further the direction. of flow of the current of heat-- ing gases adopted in accordance with this invention, (2., transversely to the longitudinal direction of the upper and lower drums is of importance to the superheater as it is solely because of this arrangement that all the superheater tubes are acted upon by equally hotgases. The latteris necessary for insuring a suflicient superheating' of the total quantity of steam generated, as at the high pressure of 60 atm. and more, the difference in temperature between the wet steam and the heating gases entering the SIIIMBXllGtIiBl' is relatively speaking small.

The heating surface, after the suppr 17s at heater, is used for heating the boiler teed water and insures a very etlirirnt utilization-oi the hot gases.

The invention may also be applied to stationary boilers.

llaving now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is:

1, in a water tube boiler provided with upper and lower drums, and a plurality of heating tlues extending in opposite directions arranged in series transversely to the length of the drums the tlue nearest the grate being divided into two parallel lines, water tubes substantially all arranged in said parallel lines and a siuiorheater and teed water heater in following lines, as and for the purpose described.

2. In a water tube boiler provided with upper and lower drums, and a plurality of heating, flues extending in opposite directions arranged in series t-ransve ,ly to the length of the drums the fine nearest the grate being divided into two parallel lines opening, into a single adjacent line, water tubes substantially all arranged in said parallel lines, a suporhoater in the adjacent line and a feed water heater in the :t'ollmving flue, as and for the purpose described.

3. In a water tube boiler provided with upper drums, a lower drum each side of the grate, and a plurality of heating; llues extending in opposite directions arranged in series transversely to the length of the drums tho flue nearest the grate being divided into 'lllltl two parallel lines, water tubes starting from said lower drum and substantially all arranged in said parallel lines. and a superheater and feed water heater in following tines, and for the purpose (lOSCJlbCtl.

t. In a water tube boiler provided with upper and lower drums and a plurality of heatingwllues extending "in opposite directions arranged in series transversely to the length of the drums the line nearest the grate being divided into two parallel. lines, water tilibes arranged in said parallel lines, a regulator at the outlet of said parallel line for the adn'iission of cold air to the heat ing gases, and a super-heaterand a feed water heater in the following lluc as and for the purpose described.

5. In a "water tube boiler provided with upper and lower drums and a plurality of heating tines extending in opposite dircetions arrai'igcd in series transversely to the length of the drums, the line nearest the grate being divided into two parallel lines, water tubes arranged in said parallel lines, superhcator in the adjacent flue, a feed water heater in a following fine and a damper in the supcrlitaiter line, said damper serving to divide gases going to said follow ing .tlue between said snperheater flunand lllf fi 'l intm'medifii flue in any desirmi prop-w tizm, as and fur the purpcse described.

6. 11 :1 Water tube boiler pm'vidwi with upper and lower drums, and a hu'ality of 11-.afing fines extendhlg in oppusiie dlrecions an-anged in serios iransversaly m 'th a Iengih of the drums PM flue nearest file being difvided iniwo parafflei films ope Lihg in) a singlfl adjacent flue, water tubes snbstmfiigxliy all aimngged in said pm- 21191 fines and sm x'ting from two drums sit uatc cm on side of'ihe gym-; superheater and a faed Waiier heater in series in flu njacent fuie a ncl in the foliowing fiues as and is? the purpose described;

7. In a waiter wm b'ciier providefi with upper and Iowa;- fimms, and 2 plurality of heating fiuas grftenfiing in opposita firms fivlons arran ed 1n series tr'ansversaiy m the grate Being divideti in two pamllel fines opening; into a single nijacent flue, Water; tubes Hanged in said parallel fiUaZS and stmrbimi ileum two drums situated; on each Si e of the grate, a superheatmand a fad Water heater in SQIiBS in the adjacent fiua zm in the following fines, and a @ampw in the suparheater fine, said damper serving t0 divide gases going is said fellow fines between smd suparheatm' 21314:: M Intermediase fine in any desired g'l'agwrfiifin as and far the pmpnse siescribgd.

' I21 testimfiny w mmaofi, I have heyeun'umet my hsmd in 12% gm snss of W10 aubscribing Witnesses.

SCHMIDT.

Witnesses EGMONT Dom rmam Q'ITD HARTMANIL 

